1. Field of the Invention
This invention relates to drill apparatus and, more particularly, to apparatus for drilling holes in the horizontal plane.
2. Description of the Prior Art
For drilling horizontally into concrete, generally two workers are required to hold and move a drill. Obviously, when manually operating a drill, successive holes will not generally be aligned parallel to each other and will not be substantially horizontally extending. Rather, because the efforts and skills of individuals change during the course of a day, and from day to day, the holes will generally be tilted slightly from the horizontal and may be at a slight angle one way or another from a desired or preferred orientation. Moreover, the use of two workers for operating a single drill is generally not cost effective as compared to using only one worker for a single drill. Moreover, the fatigue factor in manually operating a drill decreases the productivity of workers as compared to the productivity of utilizing a worker to operate a drill by remote control, as it were, which minimizes the fatigue factor.
For enlarging bridges, enlarging runways, etc., horizontal holes need to be bored into the concrete, and steel dowel pins are inserted into the holes for providing the necessary reinforcing steel bar or rebar framing for the new additions. This requires the extensive drilling of horizontal holes spaced regularly over the length of the project. As indicated in the preceding paragraph, this work has heretofore been accomplished by two men working together as a team, but with only a single drill.
Prior art drilling apparatus has been designed primarily for mining purposes and for drilling in rails for connecting adjacent lengths of rail. Such apparatus are exemplified by a number of patents, as discussed below.
U.S. Pat. No. 900,109 discloses a rail drilling machine which includes two drills. The apparatus is designed to run on wheels on the rails. The two drills are disposed below the wheels which support the framework holding the drills.
U.S. Pat. No. 1,180,554 discloses another type of rail drill apparatus which includes both rail wheels and road wheels. A single drill is supported by the apparatus.
U.S. Pat. No. 1,215,978 discloses another type of rail drill apparatus in which the drill system is movable vertically as well as horizontally.
U.S. Pat. No. 1,246,144 discloses another type of rail drill apparatus which utilizes only a pair of wheels spaced apart by an axle. A pair of drills is supported on a framework extending outwardly from the axle.
U.S. Pat. No. 1,380,991 discloses another type of rail drilling apparatus which utilizes a pair of drills extending in opposite directions. The drills are tied together through a gear system to a single source of power. The source of power is an engine supported on the same framework as used to hold the drills.
U.S. Pat. No. 416,600 discloses yet another type of rail drill apparatus utilizing a three-wheeled system. The drill is disposed between a pair of wheels at one side of the apparatus, while the opposite side of the apparatus includes only a single wheel. Power for the drill comes through a chain drive which is in turn connected through a gear system to an engine.
U.S. Pat. No. 1,844,873 discloses a horizontal rock drilling apparatus using a hydraulic ram and a cable system. The hydraulic ram is used to operate the rock drill, and the cable system is used to move the hydraulic ram. This apparatus is used for a hammer type drill, as opposed to a rotary drill. Rotary drills are disclosed in the above-discussed rail drill systems.
U.S. Pat. No. 2,143,105 discloses another type of feeding mechanism for rock drills. A chain drive system is used for moving the drill apparatus horizontally.
U.S. Pat. No. 2,152,150 discloses another type of chain and sprocket drive system for a drill. In this patent, the drilling apparatus is vertically oriented, as opposed to horizontally oriented.
U.S. Pat. No. 2,168,905 discloses a wheeled frame system for a horizontal drill in which the drill is moved relative to the wheeled frame. The frame includes two wheels on the drill portion of the frame, and a single wheel at the opposite end. The wheels are pivotally adjustable so that the frame may move in the direction of the drill or perpendicular to the direction of the drill.
U.S. Pat. No. 2,616,677 discloses a horizontally oriented auger type drill designed for mining purposes. The apparatus includes a tractor type crawler system for moving the drill apparatus transversely or perpendicularly to the direction of drilling.
U.S. Pat. No. 2,665,117 discloses another type of horizontally disposed auger drill system utilizing a wheeled carriage for moving the apparatus to the drill site. The apparatus then is supported on four legs during the drilling operation. The supporting legs are retracted in order to move the apparatus to a new drilling location. The wheels are aligned in the direction of drilling, and the apparatus accordingly does not move transversely to the direction of drilling, as for drilling successive parallel, or aligned holes.
U.S. Pat. No. 2,365,176 discloses another type of wheeled drill apparatus. The wheels allow the drill to be moved along the direction of travel of the drill.
U.S. Pat. No. 2,668,690 discloses a horizontal drilling system, designed for rock drilling, with the drill disposed beneath a supporting bar. The apparatus of the '690 patent is not on a wheeled structure, but rather is designed to be fixed in place, as in a mine, for drilling purposes.
U S. Pat. No. 2,745,637 discloses another type of mobile drilling system which utilizes both wheels and tractor treads. A drilling head is movable relative to the framework so that drilling may be accomplished at any desired angle with respect to the frame. This apparatus is designed for underground work, as in mines or tunnels.
U.S. Pat. No. 4,417,628 discloses a horizontal drilling system which is secured to a bucket of a backhoe. The drill is positioned by movement of the backhoe bucket.
It will be noted that none of the above discussed patents discloses apparatus designed for drilling horizontally into concrete or for movement in a generally horizontal direction for drilling holes spaced apart at regular intervals, as for purposes of inserting dowel pins into holes in concrete. Rather, the prior art apparatus discussed above are all designed for the specific purpose of mining or drilling into rock or earth, or else drilling into steel rails. It will also be noted that all of the patents, with the exception of the '628 patent, have long expired. Since the apparatus disclosed in each of the patents is designed for purposes other than that of the apparatus of the present invention, they are subject to the deficiencies which would be expected when apparatus designed for a completely different purpose is attempted to be adapted to a new, different application. For applications of horizontal concrete drilling, the specific prior art is the manual operation of the drills, as discussed above. In the apparatus of the present invention, the mechanization of the drilling is accomplished whereby a single operation may remotely operate a drill to provide consistent spacing and parallel orientation of successive horizontal holes in concrete.